Oil-burner heating attachment for furnaces



June 10 1924. 1,497,003 L SOUL-E OIL| BURNER HEATING ATTACHMENT FOR FURNACES Filed Sent. 30, 1922 2 sheets-shiggl June 10, 1924. 1,497,03

' L. -$OULE OILBURNER HEATING ATTACHMENT FOR FURNACES Filed Sept. 5Q. 1922 2 Sheets-Sheet. 2

T mm INVEN'FEH L,

MSW

Patented June 10, 1924.

LESLIE SOULE, OF DEDHAM, MASSACHUSETTS.

OIL-BURNER HEATING ATTACHMENT FOR FURNACES.

Application filed September 30,1922. Serial No. 591,518.

1 0 all whom it may concern;

Be it known that I, LESLIE SoULn, a citizen of the United States, residing at Dedham, county of Norfolk, State of Massachusetts, have invented a certain new and useful Improvement in Oil-Burner Heating Attachments for Furnaces, of which the following is a specification, reference being had therein to the accompanying drawings.

-T he invention relates to a new and useful improvement in apparatus for attachment to a furnace for heating by the use of an oilburner. ()ne object of the invention is to provide an apparatus employing fuel oil for heating ina furnace and which may be easily and simply installed in a furnace of ordinary construction, even though the furnace may have been originally constructed for use with wood or coal as fuel. Another object of the invention is to construct the apparatus as a unit which may be applied to an ordinary furnace without substantial change in .the furnace itself by merely removing the ordinary fire door and substituting in its place the mount for the apparatus.

Another object of the invention is to provide automatic means for completely extinguishing the burner and reigniting the burner controlled by the variation in temperature.

Another object is to provide a device for burning fuel oil in a furnace in which the feeding of the fuel to the furnace is auto-- matically stopped when the flame goes out, thus overcoming the danger incident to the use of oil burning devices in which the oil is fed to the burner by gravity or by pressure.

The invention will be fully understood from the following description when taken in connection with the accompanying drawings, and the novel features thereof will be pointed out and clearly defined in the claims at the close of this specification.

l'n the drawings, Fig. 1 is a front elevation of a hot air furnace equipped with apparatus embodying the invention, a part of the apparatus being shown in diagram.

F ig. 2 is a side elevation, partly broken away. of the apparatus shown in Fig. 1.

Fig. 3 is an enlarged sectional view of the float chamber.

Fig. 4 is a detail View of the siphon breaker employed in the apparatus.

Fig. 5 is an enlarged detail view in vertical section of the burner.

Fig. 6 is a detail view in front elevation if the parts comprising the unit shown in Fig. 7 is a side elevation of the parts shown in Fig. 6.

Referring now to the drawings, 1 represents the casing of an ordinary furnace. The special unit comprises essentially a steam generating coil, a. water connection for the steam coil, a burner, a fuel oil supply, a steam pipe connection with the burner, means wherebythe oil is fed to the burner by suction caused by the steam and whereby the oil is then atomized by mixture with the steam, a pilot. burner to initially generate steam in the coil for atomizing the oil, and a mount for the aforesaid elements so constructed as to be readily attached to the furnace in place of the ordinary fire door, said apparatus being constructed so as to be readily connected with automatic temperature controlled means for shutting off the water and for reopening and re-starting the burner.

The steam coil or generator is represented at 2 and is supplied with water through the extension portion 3 of the coil which is adapted tobe connected with a water suppipe 4 may be connected with the city water supply. The pi e 3 is provided with a needle valve 6 whic will be properly adjusted to allow the required amount of water to be admitted to the steam coil 2. By experiment this needle valve will be permanently adjusted to the proper degree of opening.

The outlet end 92 of the steam coil 2 opens into the burner 7, having a nozzle 71. The oil is fed to the said burner 7 through an inlet pipe 8 to which the oil is supplied through a pipe 9 leading from a chamber 10 provided with a float valve, as will be hereinafter more particularly described. Said chamber 10 should be so located that the level of the oil contained therein is always below the burner. @A needle valve '11 controls the amount of oil fed to the burner through the pipe 8. Said valve 11 will be permanently adjusted after due experiment to admit the requisite amount of oil to the burner.

A plate 12 serves as a mount for the water feed pipe 3 and the oil feed pipe 8, both of said pipes 3 and 8 passing through the plat 12, said plate 12 being constructed in such form as to be readily attached to the front wall of the furnace casing 1 in ply pipe 4 by a coupling 5. The supplyplace of the ordinary fuel feed door of the furnace, as shown in Figs. 1 and 2. The said plate 12 is preferably provided with lugs 13-13 similar to the lugs on the hinged edge of a furnace door, and it may be hinged to the casing of the furnace door by means of the ordinary hinge pins 11't11 which pass through holes in the lugs 1515 projecting from the casing of the furnace door.

Preferably the opposite end of the plate 12 will be attached to the door casing of the furnace by means of bolts 1616 which pass through lugs 1717 cast on the plate 12, and screw into the wall or casing of the furnace.

Located beneath the steam coil generator 2 is a gas burner 18 which is supplied with gas through a pipe 19 which passes through and is supported by the said supporting plate 12. The outer end of said gas pipe 20 is adapted for connection with a gas supply pipe 21 by means of a union 22. Said pipe 21 may be connected with the city gas supply and is provided with a shutoff valve 23, whereby the supply of gas may be entirely shut off whenever it is desired to completely shut off the heater for an extended period of time but which will ordinarily' be left open.

As long as the proper relative quantities of water and oil are fed to the burner after the burner is once ignited and steam is generated sufiicient to atomiz the oil, the burner 7 will continue ignited and supply sufficient heat to generate steam in the coil 2 and to thereby continue atomizing of the oil.

Temperature controlled means are provided to automatically shut ofl the supply of water to the steam generating coil 2 and to thereb stop the atomizing of the oil and extinguish the flame whenever the heat exceeds a predetermined temperature. The means rovided, as shown in the drawings, are as ollows:-

The pipe 3 is provided with a shut-off valve 24 located between the needle valve 6 and the end of said pipe 3 which connects with the supply pipe 4. The said valve 24: is normally open, being of ordinary and well-hown construction. A bell crank lever 25 is provided through the horizontal arm of which the stem 26 of the valve 24 passes, and said bell crank is clamped to the casing of said valve by a nut 27. A lever 28 has a pivot connection at 29 with the outer end of the bell crank 25, said lever 28 resting upon the upper end of the valve stem 26. A wei ht 3 0 on the lever 28 normally maintains tTie said valve stem 26 in its downward position holding the valve open. A spring, not shown, tends to close the valve when the downward pressure of the lever 28 due to the weight 30 is released,

The outer end of the lever 28 is connected at 31 with the lower end of achain 32 whose upper end is connected with the bell crank 33 fulcrumed at 34: to a support. A thermostat 35 is provided with a push member 36, which when the thermostat is expanded sufliciently under a predetermined temperature will engage the upright arm 33 of the bell crank 33 pushing it in the righthand direction, as viewed in Figure 1, thus turning the bell crank on its pivot and lifting the chain 32. This lifts the outer end of the lever 28, overcoming the downward force of the weight 30 and releasing the pressure of the lever 28 on the upper end of the valve stem 26. This allows the valve to respond to the closing action of its spring and completely shuts 01f the supply of water to the needle valve 6 and thus to the feed pipe 3. As soon as the supply of water already in the pipe 3 is exhausted so that there is no further supply of water to the steam generating coil 2, the atomizing of the oil will stop and the flame of the burner 7 will be extinguished. The pilot light furnished by the gas burner 18 will, however, continue burning so that as soonas the temperature falls sufliciently for the thermostat 35 to contract and thereby through the intermediate connections permit the weight 30 to press down the valve stem 26 and reopen the shut-ofl valve 24, water will be supplied to the steam coil generator, the steam coil generator being still kept at snfiicient temperature by the pilot burner 18 to generate steam when water is supplied to it, and the fuel oil in the burner 7 will again be drawn up and atomized and will be reignited.

Thefloat chamber 10 which supplies oil to the burner is kept supplied with oil from a tank 37. This is preferably accomplished through a siphon connection, the tank 37 being at a higher elevation than the float chamber 10. The siphon operates through a pipe 38 extending upward from the tank 37 whose upper end is connected with a substantially horizontal line of pipe 39, which in turn is connected with a downwardly extending pipe 40, and this latter is adapted to be connected by means of a union 41 with the pipe -12 extending upward from the float chamber 10. Said pipe 42 is permanently connected with the float chamber and forms a part of the detachable unit previously referred to. I

The supply tank 37 thus has a gravity feed to the float chamber 10 through the siphon. It is not desirable to have the oil drawn from the tank 37 any faster than suflicient to keep the chamber 10 properly supplied for feeding the burner, and therefore the chamber 10 is supplied with a float 43 carrying a valve 44 so that when the float rises above a certain point the valve 14: will become seated on the valve seat 45 at the inlet port of the float chamber and therebv are stop the flow of oil. It may sometimes happen that the float valve fails to properly close the port by reason of matter which clogs up the entrance so that the float valve wdoes not become properly seated or for some other reason the valve may fail to work. For that reason I provide means for taking care of the excess and for ultimately breaking the siphon so as to cut off the flow, even though the float valve is open. To this end I provide mechanism as follows In the upper part of the side wall of the chamber 10, I provide an outlet port 46 with which is connected an overflow pipe 47 so that if the oil in the chamber 10 rises above the bottom of the outlet 46 it will be discharged through the pipe 47 which has a downward slant. A bucket 48 is provided to receive the overflow discharge from the pipe 47. If there is an overflow from the chamber 10, it is very important to have the supply from the tank 37 completely shut off so as to prevent waste or flooding the cellar. I provide means, therefore, whereby when the overflow into the bucket 48 reaches a certain predetermined amount in weight it will cause the siphon to be broken. Within the horizontal supply section 39 of the supply pipe there is inserted a union 49 having on its upper side a branch 50 provided with a port which is controlled by a valve 51, which when closed prevents air from entering the pipe 39 and which when lifted from its seat will allow air to be admitted, thereby breaking the siphon. Said valve 51 is provided with a stem 52, which has a loose connection at 53 with a lever 54, fulcrumed at 55 in the rim of a cup 56. The outer end of the lever 54 normally rests on the rim of a cam or notched disk 57. A spring 58 coiled around the valve stem-52 is under tension and tends to keep the valve 51 seated. The upper end of said spring 58 bears against a stop 66. A weight 59 on the lever arm 54 tends to press said arm downward and if the disk 57 is turned so as to bring the notch 60 in the disk under the end of the lever 54,- said lever will be free to respond to the downward pressure of the weight 59 so that the left-hand end of the lever will drop down and the right-hand end Where it is connected with the valve stem 52 will be raised, thereby lifting the valve 51 from its seat and opening the port in the valve to admit air to the siphon, whereupon the siphon will be broken and the oil Will cease to flow from the supply tank 37 to the floatchamber 10, but as long as the lever 54 rests on the rim of the disk 57, the valve 51 will remain closed. The bucket 48 is attached to one end of a chain 61, the other end of said chain being attached at 62 to one arm of a lever 63 ful- I crumed on a stud 64, the other arm of said lever 63 carrying a counterweight 65. The

disk 57 is mounted on said stud 64 so that when the lever 63 is rocked on its pivot 64 the disk 57 will turn withit. The weight 65 counterbalances the bucket 48 when the bucket is empty. When, however, an excess of oil from the chamber 10 overflows into the bucket 48, the combined weight of the bucket and the oil will overcome the counterweight 65 and pull down the outer arm of the lever 63, thereby turning the disk 57 in a direction to bring the notch 60 into alignment with the outer end of the lever 54. This allows the weight 59 to tip down the weighted arm of the lever 54 and thereby tip up the other arm and lift the valve stem 52. This opens the air port to the pipe 39 and breaks the siphon, as already described.

The support 56 to which the lever 54 is fulcrumed is preferably formed in the shape of a cup capable of holding oil. Whenever it is desired to render the siphon operative again, oil may be poured into the cup 56 which will rundown past the open valve 51 through the port into the pipe, 39, and then if the bucket 48 is empty so as to restore the balance and return the disk 57 into position to support the outer end of the lever 54 and 'close the valve 51, the operation of the siphon will be restored.

There is provided in the bottom of the chamber 10 an outlet port controlled by a vavle 67 which may be manually operated by means of a handle 68 to draw off the contents of the tank to enable it to be cleaned out when desired.

WVhile I have shown and described one form of mechanism whereby the overflow of the excess oil in the float chamber will cause the siphon to be broken and thereby cut off the sup-ply of oil from the reservoir to the float chamber, it is obvious that various modifications of this particular mechanism may be easily made to accomplish the same result and I regard any such modified forms as coming within the scope of my. invention.

I desire and intend that the claims shall cover broadly the use of any means whereby the overflow of the excess oil will operate to break the siphon and stop the supply to the floatchamber.

Ab'affie' plate 69 is provided, as shown particularly in Figures 2 and 7, to throw the heat toward the top of the furnace, said baffle plate lying in back of the steam generating coil 2, and has a base portion 70 which extends underneath the generating coil toward the front and is-attached to the main supporting member 12. The base 70 of the baffle plate is cut out as shown at 91 underneath the generating coil and above the pilot burner 18 so as not to interfere with the direct action of the burner on the steam generating coil and also so as to allow the flame from the pilot light 18 to reach the nozzle 71 of the burner so as to ignite the atomized fuel at the burner.

To start the burner in the first place, assuming that the supply tank 37 has a suitable supply of oil, the siphon is started by pouring a little oil into the cup 56 and lifting the stem of the valve 52 to allow a sufticient quantity of oil to pass into the pipe 39 to till it, then the stem of the valve 52 will be released so as to close the valve. this assuring the proper feed of oil to the float chamber 10.

The main water valve for the supply pipe 4 will be opened to permit water to pass to the steam generating coil 2. The needle valve 6 in the water pipe 3 and the needle valte 11 in the oil pipe are both always kept open sufiiciently to admit the proper quantity of water and oil respectively to the main burner 7. The gas valve 23 will also be opened to admit gas to the pilot burner 18. The pilot light will then be ignited by hand and should remain ignited permanently or until it is desired to completely shut off the heat for an extended period of time. The pilot light will heat the generator coil 2 in a short time sufiiciently so that the water in the coil will be converted to steam, and as the steam blows out through the nozzle 71 of the burner 7 it will create a suction which will draw in oil from the chamber 10 and the oil will be atomized by the steam. If the needle Valves 6 and 11. which respectively control the water and the oil feed to the burner 7, have not been previously adjusted, they can in a short time be adjusted so as to produce the proper mixture. As soon as the proper adjustment is made and the oil is atomized, it will be ignited as it passes out of the nozzle 71 at the mouth of the burner by the pilot light 18. As long as the proper proportions of the oil and water continue to be fed, the steam coil 2 will be kept properly heated to generate steam and this will continue the operation of drawing up the oil from the chamber 10 to the burner and of vaporizing the oil. It will thus continue indefinitely.

Now if the temperature arises to a sufficiently high degree, that is, to a predetermined temperature above which it is not desired to have it go, the thermostat 35 will operate in the manner already described to close the shut-off valve 24 controlling the water supply, and then as soon as the water or steam already in the generator 2 has been exhausted, the sucticn of the oil will stop and this will extinguish the burner 7. As soon as the temperature falls again below the predetermined point, the thermostat 35 will contract and withdraw the push member 36 from the arm 33 of the bell crank 33, thus allowing the weight 30 to pull down the lever 28, again opening the valve 24 and allowing water to be fed to the steam generator. As the pilot light 18 is continually burning, the coil 2 will be kept constantly hot and will quickly generate steam again, thus causing suction of the oil to the burner 7. The oil will be vaporized, as described at. the beginning of the operation, and it will be reignited automatically by the pilot light 18, also as heretofore described.

It will thus be seen that the feed of both water and oil to the burner 7, as well as the ignition and extinguishing of the burner 7, is automatically controlled by the thermostat 35.

lVhat I claim is 1. An oil burner heating attachment for furnaces, comprising a burner, an oil supply, a steam coil connected with the burner, an oil feed tube connected with the burner, means whereby the steam causes a, suction which draws the oil to the burner, the steam also atomizing the oil, a pilot light which initially generates the steam in the coil and which ignites the burner when the oil is atomized, and temperature controlled means whereby the supply of steam is cut OE and the burner extinguished when the temperature exceeds a predetermined degree.

' 2. An oil burner heating attachment for furnaces, comprising aburner, an oil supply, a steam coil connected with the burner, an oil feed tube connected with the burner, means whereby the steam causes a suction which draws the oil to the burner, the steam also atomizing the oil, a pilot light which initially generates the steam in the coil and which ignites the burner when the oil is atomized, temperature controlled means whereby the'supply of steam is out OK and the burner extinguished when the temperature exceeds a predetermined degree, and means whereby when the temperature again falls below the predetermined point steam will again be supplied, causing a feed and atomizing of the oil, and the burner will be automatically reignited.

3. An oil burner heating attachment for furnaces comprising a burner, an oil feed chamber, means for feeding oil from the saidchamber to the burner, an oil reservoir, a siphon connection between the said oil reservoir and said oil feed chamber, an over flow discharge outlet from the feed chamher through which when the oil in the feed chamber rises above a certain level the excess will be discharged, a receptacle into which the said overflow discharges and means actuated by the weight of the overflow of oil to admit air to the siphon and 1ghereby stop the flow of oil to the feed cham- 4. An oil burner heating attachment for furnaces comprising a burner, an oil feed chamber, a steam coil having connection with the burner, means whereby the steam; crdates suction to cause the oil to be fed to the lllU burner and atomized, a water supply pipe connected with the steam coil, temperature controlled means for shutting off the water supply to the steam coil when the tempera-- ture exceeds a predetermined point, the steam supply thereby being stopped, the oil feed thereby also being stopped, and the flame at the burner extinguished,-means whereby when the temperature again falls below the said pre'detern'iined point the water supply will be 0 ened to the steam coil, and a pilot light wiich heats the said coil sufiicient to generate steam when water is supplied to the steam coil, said pilot light being located in such position as to ignite the atomized oil at the burner connected with the oil feed when the suction created by the renewed steam again causes the oil to be fed to the burner.

5. An oil burner heating attachment for furnaces, conisting of a unit comprising a steam generating coil, a burner attached to the steam coil, a water supply pipe connected with the steam coil, an oil feed pipe connected with said burner, a fuel oil feed chamber with which said oil feed pipe is connected, said chamber being so located that the level of the oil therein is below the level of the oil burner, a shut-off valve connected with the water feed pipe, temperature-controlled means for opening and closing said shut-off valve, so constructed and arranged that when the temperature rises above a pre-determined point the water supply will be entirely'shutolf, and when it again falls below a certain oint the water supply valve will b opene a pilot light which heats the steam coil sufficiently to generate steam, the oil being drawn from the oil feed chamber to the burner by suction created by the steam and there atomized and then ignited by said pilot light.

6. An oil burner heating attachment for furnaces, consisting of a unit comprising a steam generating coil, a burner attached to the steam coil, a water supply pipe connected with the steam coil, an oil feed pipe connected with said burner, a fuel oil feed chamber with which said oil feed pipe is connected, said feed chamber bein so 10- cated that the level of the oil therein is below the level of the oil burner, a shut-off valve connected with the water feed pipe,

a pilot light which heats the steam coil sufficiently to generate steam, the oil being drawn from the oil feed tank to the burner by suction created by the steam, and a mount for said described elements, said mount being constructed in such manner as to be adapted for attachment to the fire door frame of a furnace and serving as a door therefor.

7. An oil burner heating attachment for furnaces, consisting of a unit comprising a steam generating coil, a burner attached to in is below the level of the oil burner, a

the steam coil, a water supply pipe connected with the steam coil, an oil feed pipe connected with said burner, a fuel oil feed chamber with which said oil feed pipe is connected, said chamber being so located that the level of the oil therein is below the level of the oil burner, a shut-off valve connected with the water feed pipe, a pilot light located adjacent the steam coil and burner which heats the steam coil sufiiciently to generate steam, the oil being drawn from the oil feed tank to the burner by suction created by the steam, a mount for said described elements, said mount being constructed in such manner as to be adapted for attachment to the fire door frame of a furnace and serving as a door therefor, and means for detachably connecting saidmount with the fuel door casing of a furnace.

' 8. An oil burner heating attachment for .furnaces, comprising a steam generating coil, a burner attached to one end of the steam coil, a water supply pipe connected with the other end of the steam coil, an oil feed pipe connected with said burner a fuel oil feed chamber with which sai oil feed pipe is connected, said chamber being so located that the level of the oil thereshut-off valve connected with the water feed 'pipe, temperature-controlled means for tain point the water supply valve will'be J open, a pilot light which heats the steam coil sufiiciently to generate steam, the oil being drawn from the oil feed tank to the burner by suction created by the steam, an oil supply reservoir having a siphon connection with said oil feed chamber, and a float valve in said feed chamber which when the oil rises to a predetermined level in the feed chamber closes the feed inlet from the siphon.

9. An .oil burner heating attachment for furnaces, comprising a steam generating coil, a burner attached to one end of the steam coil, a water supply pipe connected with the other end of the steam coil, an oil feed pipe connected with saidburner, a fuel oil feed chamber with which said oil feed pipe is connected, a shut-0E valve connected,

ficiently to generate steam, the oil being drawn from the oil feed chamber to the burner by suction created by the steam, an oil supply reservoir having a siphon connection with said oil feed chamber, an overflow discharge pipe leading from the upper part of said fuel oil feed chamber, a receptacle into which said overflow pipe discharges, a valve which controls the admission of air to the siphon'and which is normally closed to exclude air, and means whereby when a predetermined amount of oil has been discharged from said overflow pipe into said receptacle the said valve connected with the siphon will be opened, thereby admitting air to break the siphon.

10. An oil burner heating attachment for furnaces, comprising a steam generating coil, a burner attached to one end of the steam coil, a water supply pipe connected with the other end of the steam coil, an oil feed pipe connected with said burner, a fuel oil feed chamber with which said oil feed pipe is connected, at shut-off valve connected with the water feed pipe, temperature-controlled means for opening and closing said shut-off valve, so constructed and arranged that when the temperature rises above a predetermined point the water supply will be entirely shut oil, and when it again falls below a certain point the water supply valve will be open, a pilot light located adjacent the steam coil which heats the steam coil sufliciently to generate steam, the oil being drawn from the oil feed chamber to the burner by suction created by ,the steam, an oil supply reservoir having a siphon connection with said oil feed chamber, an overflow discharge pipe leading from the upper part of said fuel oil feed chamber, a receptacle into which said overflow pipe discharges, a valve which controls the admission of air to the siphon and which is normally closed to exclude air, a pivoted member from which said receptacle is suspended in mid-air, means whereby said pivoted member is normally counterbalanced, means whereby when in its counterbalanced position the said siphon controlling valve is held closed and a trip mechanism which when the weight of the overflow receptacle is increased a .predetermined amount by the discharge of oil therein, said trip mechanism will be actuated to open the siphon controlling valve and admit air to break the siphon.

11. An oil burner heating attachment for furnaces, having a burner, a float chamber Laaaooa containing oil to be fed to the burner, said float chamber being so located that the level of the oil therein is always lower than the burner, a feed pipe leading from the said chamber to the burner, an oil supply reservoir having a gravity feed to the float chamber, said float chamber having a float valve which shuts ofl the admission of oil from the supply reservoir when the oil in the float chamber reaches a predetermined level, a Steam generator having a pipe connection with said burner, the steam operating by suction to draw the oil from the float chamber to the burner, a water pipe which supplies water to the steam generator, a shutoff valve connected with the water supply pipe, a thermostat, and operating means connecting the thermostat with the said water shut-off valve, so constructed and arranged that when the temperature exceeds a certain point the said water shut-off valve will be closed, thereby causing the stopping of the steam supply and of the suction of the gas and the extinguishing of the burner.

12. An oil burner heating attachment for furnaces, having a burner, a float chamber containing oil to be fed to the burner, said float chamber being so located that the level of the oil therein is always lower than the burner, a feed pipe leading from the said float chamber to the burner, an oil supply reservoir havin a gravity feed to the float chamber, said oat chamber having a float valve which shuts ofl the admission of oil from the supply reservoir when the oil in the float chamber reaches a predetermined level, a steam generator having a pipe con nection with said burner, the steam operating by suction to draw the oil from the float chamber to the burner, a water pipe which supplies water to the steam generator, a shut-off valve connected with a water sup ply pipe, a thermostat, operating means connecting the thermostat with the said water shut-off valve, so constructed and arranged that when the temperature exceeds a certain point the said water shut-ofl valve will be closed, thereby causing the stopping of the steam supply and the suction of the gas and the extinguishing of the burner, and a pilot light located adjacent the burner, whereby the burner is automatically ignited when the oil is drawn up and atomized by the introduction of steam.

In testimony whereof I aflix my signature.

LESLIE SOULE. 

